Hypogenic Karstification and Conduit System Controlling by Tectonic Pattern in Foundation Rocks of the Salman Farsi Dam in South-Western Iran

Authors: Mehran Koleini, Jan Louis Van Rooy, Adam Bumby

Abstract:

The Salman Farsi dam project is constructed on the Ghareh Agahaj River about 140km south of Shiraz city in the Zagros Mountains of southwestern Iran. This tectonic province of south-western Iran is characterized by a simple folded sedimentary sequence. The dam foundation rocks compose of the Asmari Formation of Oligo-miocene and generally comprise of a variety of karstified carbonate rocks varying from strong to weak rocks. Most of the rocks exposed at the dam site show a primary porosity due to incomplete diagenetic recrystallization and compaction. In addition to these primary dispositions to weathering, layering conditions (frequency and orientation of bedding) and the subvertical tectonic discontinuities channeled preferably the infiltrating by deep-sited hydrothermal solutions. Consequently the porosity results to be enlarged by dissolution and the rocks are expected to be karstified and to develop cavities in correspondence of bedding, major joint planes and fault zones. This kind of karsts is named hypogenic karsts which associated to the ascendant warm solutions. Field observations indicate strong karstification and vuggy intercalations especially in the middle part of the Asmari succession. The biggest karst in the dam axis which identified by speleological investigations is Golshany Cave with volume of about 150,000 m³. The tendency of the Asmari limestone for strong dissolution can alert about the seepage from the reservoir and area of the dam locality.      

Keywords: Asmari Limestone, Karstification, Salman Farsi Dam, Tectonic Pattern.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1336572

References:

[1] Klimchouk, A. (2007). Hypogene Speleogenesis: Hydrogeological and Morphologenetic Perspective. National Cave and Karst Research Institute, Carlsbad, NM, 106 pp.
[2] Milanovic, P.T. (1997). Reservoirs in karst: Common Watertightness Problems, in Guney, G., and Johnson, A.I., eds., Karst Waters and Environmental Impacts, Rotterdam, A.A. Balkema, p. 397–400.
[3] Folk, R. L. (1959). Practical Petrographic Classification of Limestones: American Association of Petroleum Geologists, 43, pp.1-38.
[4] Dunham, R. J. (1962). Classification of Carbonate Rocks According to Depositional Texture: American Association of Petroleum Geologists.
[5] Choquette, P. W. and Pray, L. C. (1970). Geologic Nomenclature and Classification of Porosity in Sedimentary Carbonates: American Association of Petroleum Geologist, vol. 54, no.2.
[6] Flugel, E. (2004). Microfacies of Carbonate Rocks Analysis, Interpretation and Application: Springer-Verlag.
[7] Palmer, A.N. (1991). Origin and Morphology of Limestone Caves, Geological Society of America Bulletin, v. 103, p 1.
[8] Erinc, S. (1960). Karstic Features in the Konya Region and Inner Part of the Taurus Mountains. Review of Turkish Geog. Society, 20: 83-106.
[9] Atalay, I. (1987). Introduction to Geomorphology of Turkey (in Turkish). Ege University, Faculty of Letters Pub. Nu: 9, 454 pages, Izmir.
[10] Gunn, J. (2004). Encyclopedia of Caves and Karst Science. New York: Fitzroy Dearborn, 902p.
[11] Bakalowicz, M. (2005). Karst Groundwater: a Challenge for New Resources. Hydrogeology Journal 13, 148–160, doi, 10.1007/s10040-004-0402-9.
[12] Klimchouk, A. and Ford, D. C. (2009). Hypogene Speleogenesis and Karst Hydrogeology of Artesian Basins. Proceedings of the conference held May 13 through 17, 2009 in Chernivtsi, Ukraine. Ukrainian Institute of Speleology and Karstology Special Paper 1.
[13] Ford, D.C. and Williams, P.W. (1989). Karst Geomorphology and Hydrology. Unwin Human, London, 601 pp.
[14] Worthington, S.R.H. and Ford, D.C. (1995). High Sulphate Concentrations in Limestone Springs: an Important Factor in Conduit Initiation. Environmental Geology 25. 9-15.
[15] Hill, C.A. (2000). Sulphuric Acid Hypogene Karst in the Guadalupe Mountains of New Mexico and West Texas. In: Klimchouk, A., Ford, D.C., Palmer, A.N. and Dreybrodt, W. (Eds.), Speleogenesis: Evolution of karst aquifers. National Speleological Society, Huntsville, 309-316.
[16] Palmer, A.N. (2000). Hydrogeologic Control of Cave Patterns. In: Klimchouk A., Ford D., Palmer A. and Dreybrodt W. (eds.), Speleogenesis: Evolution of Karst Aquifers. Huntsville: National. Speleological Society, 77-90
[17] Klimchouk, A. (2000). Speleogenesis under deap-seated and confined settings.- Speleogenesis. Evolution of karst aquifers, 244-260. Klimchouk A.
[18] Stucky-Electrowatt joint venture. (1996–2004). Salman Farsi Dam-Mission Reports.
[19] Fazeli, M. A. (2006). Construction of Grout Curtain in Karstic Environment case study: Salman Farsi Dam. Environ Geol, 51: 791–796 DOI 10.1007/s00254-006-0397-8, Springer-Verlag.
[20] Mohammadi, Z. and Raeisi, E. (2007). Hydrogeological Uncertainties in Delineation of Leakage at Karst Dam sites, the Zagros Region, Iran. Journal of Cave and Karst Studies, v. 69, no. 3, p. 305–3